1. Field of the Invention
This invention relates to a chart drawing processing method and device, and computer-readable medium recording a program of the same. More specifically, the present invention relates to a processing method and device for drawing a polygonal chart using polygon by computer, and a computer-readable medium storing a program for causing a computer to function as the processing device.
2. Description of the Related Art
Analyzing techniques using a radar chart include a determination technique of calculating areas of graphics, each of which is made by drawing lines between the scores plotted on indicator axes for evaluation items on the radar chart (hereinafter referred to as “radar chart graphic”), and simply comparing the areas to put an object with a bigger area before the others.
For example, a determination technique using a radar chart described in Patent Document 1 determines superiority and inferiority of determination objects by displaying two radar charts of the determination objects side by side, calculating areas of the two radar chart graphics, and comparing the area of base graphic calculated in predetermined procedure with the calculated area of the radar chart.
(Patent Document 1: Japanese Patent Laid-Open No. 2002-197250)
In such an analyzing technique using a radar chart, however, areas of a radar chart graphic representing objects to be determined or evaluated may not accurately reflect the total scores of evaluation for the objects.
Some physical relationship between scores plotted on indicator axes of radar charts forming a radar chart graphic may lead an error in intuitive determination on sizes of areas of the radar chart graphic.
With reference to FIGS. 1 to 3, an erroneous evaluation occurred when evaluation objects represented on radar charts are evaluated by using areas of the radar chart graphic.
FIG. 1 is a diagram showing an example of a display of a radar chart. A radar chart shown in FIG. 1 is based on a radar chart with an evaluation scale of 0-5 on an indicator axis of each evaluation item for eight evaluation items (A-H). Radar chart graphics representing three evaluation objects of Object a, Object b and Object c are drawn on the bases of the radar charts.
In a radar chart shown in FIG. 1, it is difficult for a user to recognize what comprehensively the best among the three evaluation objects at a glance. If visual sizes of radar chart graphics for respective objects are intuitively compared, Object b or Object c may be recognized as the best.
Accuracy of this evaluation is verified by using total scores of objects, areas of radar chart graphics and visual sizes of the graphics.
FIG. 2 is a diagram showing examples of data tables and radar chart graphics of three evaluation objects. FIG. 2A is an example of a diagram showing a data table for Object a, FIG. 2B is a diagram showing an example of a data table for Object b, and FIG. 2C is a diagram showing an example of a data table for Object c. In each data table, scores and areas of respective evaluation items, a total score, and an area of a radar chart graphic are recorded. FIG. 2D is a diagram showing an example of a radar chart graphic representing Object a, FIG. 2E is a diagram showing an example of a radar chart graphic representing Object b, and FIG. 2F an example of is a diagram showing a radar chart graphic representing Object c.
FIG. 3 is an example of a table showing ranking of each object in total scores, areas of radar chart graphics, and visual sizes of radar chart graphics. According to the data tables shown in FIG. 2A to FIG. 2C, ranking of objects in the total scores is; the first place=Object c, the second place=Object b, and the third place=Object a. Ranking in areas of the radar chart graphics is; the first place=Object a, the second place=Object b, and the third place=Object c. As mentioned above, according to intuitive evaluation of objects in areas of the radar chart graphics, Object b or Object c are seemingly recognized as the best, thus; the first or second places=Object b or Object c, and the third place=Object a.
As shown in FIG. 3, ranking of the objects are not the same for total scores, areas of radar chart graphics and visual sizes of radar chart graphics. If objects are evaluated for superiority and inferiority based on areas of their radar chart graphics, the ranking of evaluation may be incorrect. Thus, areas of radar chart graphics representing evaluation objects do not accurately correspond to the total scores of the evaluation items.
It is difficult for a user to intuitively determine magnitude relationship between radar chart graphics based on impressions the user got from the sizes of graphics. For objects having similar total scores may be evaluated incorrectly. This is because characteristics in shapes of radar chart graphics are not suitable for comparing areas, and a combination of locations of scores on indicator axes of radar charts may change the user's impression on the size of the graphic.
A conventional evaluation method by using areas of radar chart graphics, for example, a processing method disclosed in Patent Document 1 evaluates evaluation objects only by drawing the evaluation objects on radar charts and simply comparing the areas of the drawn radar chart graphics. Therefore, magnitude relationship with evaluation objects in total scores does not correspond to magnitude relationship with areas of radar chart graphics, which leads incorrect evaluation.
In order to cover ambiguity in such evaluating process by using areas of radar chart graphics, a system exists which enables a user to check total scores of evaluation objects by displaying data tables for scores of evaluation items of evaluation objects as well as radar charts. In such a conventional system, however, final evaluation needs to be done by a user who checks numeric values on the displayed data tables. Thus, a user does not take advantage of convenience of comparison between radar charts.
As such, the conventional arts do not take account of how to accurately reflect total evaluation scores of evaluation objects on areas of radar chart graphics. Accordingly, incorrect evaluation result caused by simple comparison of areas of radar chart graphics for evaluation objects cannot be eliminated. Characteristics in a shape of radar chart graphic also make it difficult for a user to intuitively evaluate superiority and inferiority of radar chart graphics by comparing them.